Hey guys new here, I had something really strange happen recently with my truck. Here's the mod list to help, if it matters...
Afe twin cai
Afe cat back exhaust
Afe charge pipe intercooler to throttle body pipe
sct live wire 5 star tune 91oct performance, 91oct gas mileage/towing.
So I had the performance tune loaded when pulling this time, my live wire wasn't on at the moment so I couldn't see boost pressure, on the performance tune it will run 19-20psi Max. But anyways here's the issue, I've pulled my gt500 on a twin axel trailer and have gotten 17-18mpg, I was pulling my Harley on a motorcycle trailer two days ago and got 7mpg no check engine light or anything also my truck had nothing for power. Like I said the live wire wasn't on so I didn't see what it was running for boost. Is this a boost leak some where or a bad spark plug or even the infamous oil problem when you need the catch can?

 

Why are you towing with a PERF tune? Performance tune is not for towing. When you tow use tow tune, when you want performance use performance..

 

Honestly I've pulled my car on the performance tune... I don't think that has much to do with it... all tuning for performance is, is just timing and boost psi and other things obviously to make it all work. The computer will pull timing automatically if anything gets too out of hand. And not to mention this Harley maybe weighs 500lbs and it was a aluminum motorcycle trailer.

 

I'm going to hook up the live wire in two days when I have some free time and drive a bit to see if it will throw any codes and what it's running for boost.

 

If you have around 40k miles on those spark plugs I would replace them with some Motorcraft SP534's. They should come gapped @ .030 if your running a tune you may even want to tighten them down to .028